The general objective of the proposed study is to analyze inhalant use from an intergenerational, life course developmental perspective. The proposed study capitalizes on over 25 years of research that has followed a nationally representative sample of adolescents into adulthood, and is presently collecting identical retrospective and prospective measures of inhalant use and related information from their adolescent children, the replacement generation, and retrospective data on inhalant use and related information from the spouses and parents of the focal generation. The specific objectives are: (1) To study developmental patterns of initiation, continuation or maintenance, and cessation or suspension of inhalant use in the focal generation of respondents, including subpopulations defined by sociodemographic characteristics; (2) To study sequencing of initiation and suspension of inhalant use relative to other substance use, other problem behavior, and potential risk and protective factors for initiation and suspension, in the focal generation, including subpopulations defined by sociodemographic characteristics; (3) To study the comorbidity of inhalant use with other problem behaviors (a) developmentally, across the life course, for the focal respondents, (b) intergenerationally, comparing patterns of comorbidity in adolescence and young adulthood, for the focal generation and their children, and (c) including comparisons of comorbidity developmentally and intergenerationally across sociodemographic subpopulations; (4) To study the risk and protective factors for inhalant use, including other problem behaviors as potential risk factors for inhalant use and inhalant use as a potential risk factor for other problem behaviors (a) developmentally, (b) intergenerationally, and (c) including comparisons of comorbidity developmentally and intergenerationally across sociodemographic subpopulations; (5) To study the patterns, prevalence, and correlates of inhalant use among three classes of high risk youth (i.e., children of drug users, school dropouts, and gang members); and (6) To study the long term consequences of adolescent inhalant use on adult outcomes for the focal generation, controlling for prior (adolescent) indicators or precursors of the adult outcomes, and comparing results across sociodemographic subpopulations.